Electrolift



March 31, 1936. c E OH N 2,035,243-

BLECT'ROLIFT Filed April 9, 1932 Patented Mar. 31', 1936 PATENT OFFICE Carl E. Johnso Pasadma, Application April 9, 1932. Serial Nd. 604.25! 18 Claims. (cl. so-'52) -My invention relates to thrust-exerting devices, and more particularlyto. a novel structural combination in. which an electric motor or other rotary drive means is effective in 'producmg a reciprocating movement of a pistodthrough hydraulic means. r

,The invention finds particular utility in installations wherein it'is desirable to be able to build up rather large thrust forces with aof current consumption, and it is a primary object of the invention to combine in a single structure a hydraulically actuated piston, an impeller or'other pump means for supplying liquid under pressure to,th is piston,

and a drive means for the pump.

,Further objectsof the invention lie in the provision of a structure wherein the motor or other drive means is enclosed by the same shell which encloses the remainder of the parts, and.

in which the motor or other drive means can v itself be surrounded by-the operating liquid,

Further objects lie in a novel cooling system V for the motor.

Other objects and advantages the invention lie in the provision of a novel assembly which can be readily adapted to difl'erent installations and in which the elements are mounted in a novel manner. r

Still further objects lie in the positioning of the pump means in spaced relationship with the piston, and in the novel shock-absorbing system acting between the, piston and the shell.

The invention also includes a novel protector for the junction of the reciprocating'rod and the shell.

Still other objects and advantages of the invention will be apparent to those skilled in the art from the following detailed disclosure of the preferred form of the invention.

Referring to the drawing, v Fig; l is a vertical sectional view of the assembled structure; l

.Figs. 2 and 3 are horizontal sectional views taken on the corresponding-lines of Fig. 1.

The invention will be shown and described in conjunction with an electric motor, but it should be understood that other types of drive means maybe utilized. V r

Referring particularly to Fig. '1, the invention includes an outer shell 'I 0 of cylindrical form andclosed at its upper and lower ends by heads I I and I2 which are perferably removable with respect to the outer shell and cooperate therewithin providing an enclosing structure; These heads are held in clamping relationship with this wall being hereinafter termed an auxiliary wall. As best shown in Fig. 3, this wall includes lugs 2! extending outward from its periphery 22 .so as to centralize the auxiliary wall 20 with respect to the outer shell ID, the periphery 22 cooperating with'the inner wall of the outer shell in in defining spaces 23 between the lugs 2i.

Suspended as by studs 24 from the auxiliary. wall is a sectional shell 25 of a drive means 26 which is preferably in the form of anelectric motor including a stator 21 mounted in the shell 20 25 and a rotor 28 secured to a shaft 29. This shaft may be journalled by a bearing 30 mounted in a lower wall 3i 0! the shell 25 and by a bearing 32 mounted in the auxiliary wall 20, this shaft extending upward beyond the wall 25 29 as shown. g

. Resting on the spacers I9 is a wall 35 providing lugs similar. to the lugs 2! so that the periphery of this wall is spa'ced from the outer shell 10, as best shown inl 'ig. 1. An inner 3o shell 38 rests on the wall 35, being centralized with respect to the outer shell III by a ledge from the outer shell to form passages 42, as

shown, these lugs providing openings through which the'rods I3 pass. The upper ends of the 40 rods I3 are threaded so as to receive nuts 43 which may be threaded downward on these rods to engage the collar 40 and thus cooperate with the spacer means at the lower end of these rods in retaining the walls 20- and 35, as well as the 45 inner shell 38, in flxedaxial position, the nuts 43 being tightened prior to the time that'th'e upper head Ii is secured in place. I

,The outer and inner sh lls I0 and 38 cooperate in defining an annular space 48, the

upper end thereof communicating with the upper interior of the shell I0 and with the 'upper end of a piston chamber 48 defined inside the inner shell 38 above-the wall 35, this com- Slidably disposed in the piston chamber 48 is a piston 52 which moves in substantially fluidtight relationship with the inner wall of the inner shell 38. A stop means 53 .extends downward from the piston and is adapted to engage the ledge 39 of the wall 35 when the piston is in a lower position.

An operating rod 54 is secured to the piston and extends upward through an opening 55 of the upper head II, it being preferable to provide a seal 56 atthis point. In the embodiment shown in Fig. 1, this seal comprises an annular flexible member 51 providing a. lower portion which engages a surface of the rod 54 in wiping relationship, this member being positioned in a cavity 58 and retained therein by a gland 58.

A spring 66 is preferably disposed around the rod 54 and resiliently supports a plate 6! which engages an annular lip 62 of the head it prior to the time that the piston 52 engages the collar 46. The spring 66 thus acts as a resilient means for limiting the upward movement of the piston 52.

It is usually preferable to provide a resilient means for impeding the return movement of the piston 52. In the embodiment shown in Fig. 1 a spring 65 surrounds the rod 54 and of the shell ID. This is'accomplished in the preferred embodiment of the invention by means of a flexible member 18 secured to the plate 61 and the boss 66 and being expansible to compensate for the movement of the rod 54. In the preferred form of the invention this flexible member is in the form of a piece of oiled duck creased to fold in the shape of a bellows, and

it "is usually desirable to interpose a spacingmeans H therein, this spacing means comprising a relatively weak spring disposed immediately inside the flexible member '76 to hold this member in spaced relationship with the spring 65. a V I The interior of the outer shell I6 is filled. to a level H with oil or other operating liquid having relatively good dielectric properties so that opposite ends of the piston chamber 48 contain this operating liquid. 'The piston 52- is moved by hydraulic force set up when the op erating liquid is pumped from the upper end of the piston chamber 48 to the lower end thereof. This pumping action is efiected by a pump means in the form of an impeller '15 connected to the motor shaft 29 and preferably disposed in the lower end of the piston chamber 48 so as to intake through a port 16 formed centrally in the wall 35 and so as to discharge directly into the lower end of the piston chamber 48 in an outward direction.

Various types of pump means may be utilized,

but in the preferred embodiment of the inven-.

tion I prefer] to utilize an impeller having an uppershroud Tl with vanes 18 depending down- ;ward therefrom, but being spaced a slight distance wro'm the wall 35. The passage formed between the vanes 18 of the impeller are always 2,085,818 formed by an arcuate hood 5!! of the collar 46. V

in open communication with the port I6 and with the interior of the piston chamber so that when the motor 26 is de-energized the weight of the piston 52 and rod 54 returns the operating liquid, previously displaced, through the passages of the impeller in a reverse direction. It will be understood that the stop means 53 extends downward so as to engage the ledge 39 prior to the time that the piston 52 engages the impeller 15, thus preventing engagement between the piston and the impeller in the event that the spring 65 does not act to stop the return of the piston prior to the time the stop means 53 engages the'ledge 39. When themotor 26 is again energized it will be clear that operating liquid is drawn from the upper end of the piston chamber 48 through the annular space 66 and into an intake. passage 19, disposed between the walls and 35, and thence 'into the port It to the intake of the impeller, the

liquid being discharged under high pressure into the lower end of the piston chamber so as to exert an upward force on the piston 52.

It is preferable to utilize the pump means for a dual purpose, namely, to advance the piston 52 and to cool the motor 26 or other drive means. small holes 86 through the lower wall 3| of the motor shell 25, and by providing ports 82 in the auxiliary wall 28 which communicate with the interior of the motor shell and with the intake of the impeller 15. Thus, when this impeller is rotating it not onlyrdraws the operating liquidthrough the intake passage 19, but sets up a by-pass flow indicated by the arrows 84, this flow being downward around the outside 'of the motor shell and upward through the holes 80 and through the motor, this operating liquid then flowing through theports 82 and into the impeller 15. This effectivelycools the motor at all times. l

In addition, it is desirable that the circulation through the motor 26 be maintained even though the piston 52 is in an advanced position. This is accomplished by providing relatively This is done by forming relatively small openings 85 through the pisto'n. Thus,

. ating liquid. If these openings were not provided a body of gas would be entrapped immediately below the piston 52 when this operating liquid is poured into the shell. a

The current to the motor may be supplied by any suitable means, butin the preferred embodiment the current is conducted through terminals 96 mounted in insulated relationship with respect to the upper head H, as best shown in Figs. 1 and 2. Theseterminals preferably extend below, the level H and through a'gas chamber 960, formed in the enclosing structure above this level so as to be connected to conductors,9l at a point below the surfaceof the operating liquid, these conductors extending downward through the annular space '46 and into the motor 26. r

'The utilization of an impeller having but a single shroud is a very desirable feature, espe- -'impeller can be rea cially when such an impeller is positioned so as to discharge directly into the lower end of the piston chamber. From a 'manufacturing standpoint, the pressure developed by such an varied either by changing the outer diameter of the impeller, or by changing the distance between the lower edges of the vanes 18 and the wall 35. This latter change also varies the amount of liquid pumped by the impeller and can be made either by turning down the vanes l8'or by changing the height of the spacers Is. It is further an importantv feature of the invention that the impeller discharge directly into one end 01 the piston chamber so that there is a minimum of turbulence as the operating fluid discharges. If the impeller discharges into curved passages, addi tional losses are set up.

,The particular manner of structurally connecting the different elements is also an important feature of the invention. The apparatus can be readily adapted to different lengths or stroke by suitable design of the inner and outer shells without changing the design or size of the motor. Further, the type of motor mounting herein shown is of advantage in view of the fact that motors of diilerent size may be utilized to control the rate at which the rod 54 is advanced.

Finally the structural connection between the elements is,such that the parts are easily assembled with a minimum of bolts, and are rigidly held in place through the action of the rods. 83 and the spacing means positionedthereon;

The completestructure maybe mounted in any suitable 3 mane'r as by a clev'ls 95 extending downward from the lower head l2, it being understood that the thrust is transmitted by the upper end of the rod 54. to any desired ep- 10 paratus by any suitable connecting means.

I claim as my invention: 1 1. In combination in a. self-contained thrustproducing device: a shell defining a piston chamber; a piston reciprocable in said piston chamber, said piston chamber being sub-' stantially filled on opposite sides of said piston connected to said pump means; and by-pass means communicating between the intake and discharge of said pump means and including a passage through said motor and through which by-pass means moves a portion of the operating liquid pumped by said pump means when said motor means is operating. Y 2. In combination in a self-contained thrustproducing device: an outer shell containing a body of operating liquid and including a PiS-e ton chamber; a piston reciprocable in said piston chamber; an impeller means in said outer shell and spaced from said piston, said impeller providing intake meanscommunicat ing' with one side oi said piston and discharge means communicating with the other side of said piston, whereby when said impeller means is rotatedthe liquid on one side of said piston is transferred to the other sidef'of said piston to .displace same, the displaced liquid returning through said impeller means when said impeller means is stationary; and an electric motor positioned in said liquid at one end'ot said piston and operatively'connected to said impeller means to rotate same.

3. In combination in a self-contained thrustproducing device: an outer shell containing an operating liquid; an inner shell mounted in said outer shell and defining a piston chamber, said inner shell being spaced from said outer shell to define an annular space communicating at one end with one end of said piston chamber; a piston reciprocable in said piston chamber, said piston chamber being filled on opposite sides of said piston with saidoperating liquid; a plunger operatively connected to said piston and extending from said outer shell; an impeller intaking from oneend of said piston chamber and discharging into the other end thereof whereby said piston is moved, the liquid pumped by said impeller passing "through said annular space; and drive means for said impeller and including an electric motor mounted in said outer shell at one end of said inner shell and positioned directly beneath said inner shell'in said operating liquid. i

4. In combination in a self-contained thrustproducing device; an outer shell containing an operating liquid; an inner shell mounted in said outer shell and defining a piston chamber, said inner shell being spaced from said outer shell to define an annular space communicating at one end with one end of said piston chamber; a

' pistonreciprocable in said piston chamber, said piston chamberbeing filled on opposite sides of said piston with said operating liquid; a plunger operatively connected to said piston and extending from said outer shell; a wall extending across said inner shell and providing a port' communicating with said piston chamber; an impeller adjacent said port and moving said operating liquid therethrough; and drive means in the form of an electric motor below said wall and operatively connected to said impeller.

5. In combination in a self-contained thrustproducing device:, an outer shell, containing an operating liquid; an inner shell mounted in said outer shell and defining a. piston chamber, said inner shell being spaced from said'outer shell to define an annular spacemommunicating at one end with one end of said piston chamber; a piston reciprocable in said piston chamber, said piston chamber being filled on opposite sides of said piston with said operating liquid; a plunger operatively connected to said .piston and extending from said outer shell; a wall extending across said inner shell and providing a port communicating with said piston chamber; an auxiliary wall spaced from said wall and cooperating therewith to' define a passage communicating with said annular space; an impeller adjacent said port and moving operating liquid from one end of said piston chamber to the other through said passage and said annular space; and electric motor means below said auxiliarywall and operatively connected to said impeller means. I

g 6.. In combination in a self-contained thri1streducing device: an outer shell containing an operating liquid; an inner shell mounted in said outer shell and defining a piston chamber, said inner shell being spaced from said. outer shell to define an.-annular space communicatingat one end with one end of said piston chamber; a piston reciprocable in said piston chamber, said piston chamber; being filled on opposite sides of said'plston with said operating liquid; a plunger operatively connected to said piston and extending from said outer. shell; a wall extending across said inner shell and providing a port communicating with said piston chamber; an

.auxiliary wall spaced from said wall and cober, opposite ends of said piston chamber being and defining a pistonchamber; means including 7 operating therewith to define a passage com-- municating with said annular space; an impeller adjacent said port and moving operating liquid from one end of said piston chamber to the other through said passage and said annular space; an electric motor mounted below said auxiliary wall and in said operating liquid in said outer shell; and 'walls defining ports communicating with the interior of said electric motor and communicating with said impeller means whereby a flow of said operating liquid is set up through said electric motor.

7. In combination; a shell; s. wall extending across one end of said shell and cooperating with said shell in defining a piston chamber, said wall providing a port communicating with said piston chamber; a piston reciprocable in said piston chamber, said piston chamber being substantially filled with an, operating liquid on opposite sides of said piston; an impeller means in said piston chamber and intaking from said port and discharging into one end of said piston chamber; and an electric motor on the opposite side of said wall from said impeller means for driving said impeller means to transfer the operating liquid from one side of said piston to.

v the interior of said piston chamber.

9. In combination: an outer shell; heads closing opposite ends of said outer shell; on inner shell in said outer shell and defining a piston chamber; a piston movable in said piston chamflowing said operating liquid from one end of said piston chamber to'the other when said pump means is operating.

10. In combination: anouter shell; heads closing opposite ends of said outer shell; rods extending betwensaid heads inside saidouter shell to retain said heads in contact with said outer shell; an inner shell in said outer shell said rods for axially positioning'said inner shell with respect to said outer shell; a piston mov- 11. In combination:.-an outer shell; heads closing opposite ends of said outer shell; rods extending between saidheads inside said outer shell; a wall inside said outer shell and through which said rods extend; an inner shell in saidouter shell, onevend of said inner shell abutting against "said wall, said inner sheilgdefining 'a piston chamber; a" collar atthe other end or said inner shell and through which saidrods" ex tend; means on said rodsjfor spacing-said,

the upper end of said outer shell and mounted to collar and said wall thereon in a manner to retain said inner shell therebetween; a piston movable in said piston chamber, opposite ends of said piston chamber being filled with an operating liquid; pump means for moving operating liquid from one end of said piston chamber which said rods extend; an inner shell in-said outer shell, one end of said inner shell abutting against said wall, said inner shell defining a piston chamber; a collar at the other end of I said inner shell and through which said rods extend; motor means in said outer shell; mounting means for said motor means and through which said rods extend; spacer means adjacent said rods for spacing said mounting means, said wall, and said collar with respect to each other whereby said inner shell is clamped between said wall and said collar; a piston movable in said piston chamber, opposite ends of said piston chamber being filled with an operating liquid;

' and pump means driven by said motor means for movingoperating liquid from one end of said piston chamber to the other to advance said piston. r a

13; In combination in a self-contained thrustproducing device: a shell containing a body of operating liquid and defining a piston chamber; air'electric motor positioned insaid shell directly beneath said chamber to be surrounded by said operating liquid in a manner to be cooled thereby; a piston in said chamber; pump means driven by said motor and intakin'g-irom one end of said piston chamber and discharging into the other end thereof to move said piston; and a plunger operated by said piston and extending through a wall of said shell. I

1,4. In combination in a self-contained thrustproducing device: an outer shell; a plunger in reciprocate therein; a rotatable shaft in the lower end oi said outer shell and mounted to rotate about an axis common to the extended axis of said plunger; an electric motor for rotating said shaft and positioned in said lower end of said outer shell, said outer shell containing an .operating liquid surrounding saidelectric motor; a piston on said plungen and pump means driven by said shaft and positioned between 'said electric motor and said plunger for forcinga portion of,said operating liquid into pressuralcontact with said piston to advance said plunger.

15. In combination in a self-contained thrustproducing device: walls forming a piston chamsubstantially filled with an operating liquid and disposed in superposed relationship, said 1walls including a wall separating said piston chamberirom'said intakepassageand providing a port; an impeller in said piston chamber and provlding a central intake means opening directlyon said port whereby operating liquid is drawn from said intake passage and through said port by said impeller and discharged into said pistonchamber; a piston movable in said piston chamber under the action of said operating liq- 60 her, an intake passage, and a motor chamber uid reaching said piston" chamber; a motor in. a

said motor chamber and driving said impeller; and walls defining an opening in said walls torming said motor chamber and communicating between said intake chamber and said motor chamber, said openings conducting operating liquid through said motor chamber under the iniiuence of said impeller.

v 16. In combination in a self-contained thrustproducing device: an enclosing structure containing an operating liquid, the upper portion of said enclosing structure defining a gas cham ber; walls forming a piston chamber in the upper portion of said enclosing structure; an 7 electric motor in the lower portion of said enclosing structure below the surface of said operproducing device;

ating liquid; a pump means driven by said electric motor and discharging into said piston chamber; a piston movable in said piston chamher; and conductor means extending through said enclosing structure and into said gas chamber and thence extending downward outside said piston chamber to said electric motor for supplying current thereto.

17. In combination in a self-contained thrustbody of operating liquid; a head extending across one end of said outer shell and including an plunger extending through said opening; a piston movable upward and downward in said outer shell and secured to said plunger; a spring surrounding that portion or said plunger extending beyond said head; means into contact with said an outer shell containing a associated with said plunger and engaging said spring when said piston nears its lowermost position to compress said spring; a pump means in said outer shell for forcing operating liquid piston to advance said plunger; and a motor in said outer shell and operatively connected to said pump means. 18. In combination in a self-contained thrustproducing device: an outer shell containing a body of operating liquid; a head extending across one end of said outer shell and including an opening therein; a plunger extending through said opening; a piston movable upward and downward in said outer shell and secured to said plunger; a shoulder movable with said plunger and approaching said head when said plunger is moving downward; a compression spring around said plunger and compressed between said shoulder and said head when said plunger is close to its lowermost position to cushion said piston and plunger; a flexible protecting member around "said spring and secured at its one end to said head and at its other end to said plunger; a pump means in said outer shell for forcing operating liquid into contact with said piston to advance said plunger; and

a'motor in said outer shell and operatively connected to said pump means.

CARL E. JOHNSON. 

